We have recently reported that the concentration of piperidine in the mouse brain substantially increases during sleep. This study is designed to provide an experimental analysis of the mechanisms leading to the observed increase of piperidine in the mammalian brain during dormancy (apparent sleep), and to attempt to correlate the piperidine level in the brain with the individual phases of electroencephalographic activity. The experiments will be performed on inbred and on axenic mice. The methods used in this study will consist of: 1) thin layer chromatography for separation of dansylated amino acids and amines from the brain homogenate; 2) quantitative mass spectrometry for identification and quantitation of fractions obtained by thin layer chromatography; 3) liquid scintillation spectrography for quantitation of radioactive fractions obtained by thin layer chromatography; 4) continuous recording of the electroencephalographic activity using gross implanted electrodes; 5) continuous recording of the electromyographic activity from the dorsal neck muscles, and 6) instantaneous evaluation of the EEG and EMG activity.